The present invention relates to an arsenic sorbent that takes up arsenic from an arsenic-contaminated environmental substance or the like, and may be used as a purification material, and a method of purifying an arsenic-contaminated substance.
Arsenic (As) is an environmental pollutant that damages health when taken into a human body even in a small amount.
Therefore, technology that effectively removes arsenic from arsenic-contaminated water, soil, or the like has been desired.
Examples of a water-soluble arsenic compound include arsenious acid, arsenate, and an organic arsenate.
Arsenic is present as arsenious acid in ground water under a reducing environment, and reacts with oxygen on the ground to form arsenate.
Since arsenious acid and arsenate are highly toxic, it is important to remove those.
Technology that causes a natural trace element such as arsenic to be adsorbed on the surface of a mineral has been known. For example, Vasso G. Alexandratos, Evert J. Elzing a, Richard J. Reeder, “Arsenate uptake by calcite: Macroscopic and spectroscopic characterization of adsorption and incorporation mechanisms”, Geochimica et Cosmochimica Acta 71 (2007) 4172-4187 (“Document 1”) describes that calcite (CaCO3) adsorbs arsenate.
However, the arsenate adsorption ability of calcite is insufficient for purifying an arsenic-contaminated substance. Moreover, calcite has poor arsenate adsorption stability.